Phorbol esters parallel effects on tumor promotion, insulin release and calcium ionophoresis.
The tumor promoters 12-O-tetradecanoylphorbol-13-acetate (TPA) and phorbol 12,13-didecanoate (PDD) both stimulated insulin release from rat pancreatic islets and facilitated ionophore-mediated calcium transport in liposomes, the latter effect not resulting from a change in viscosity of the liposomial matrix. Phorbol and 4 alpha-phorbol 12,13-didecanoate (4 alpha-PDD), which fail to cause tumor promotion, also failed to stimulate insulin release and ionophore-mediated calcium transport. An alteration of calcium transport may represent a fundamental event in both the early (insulin release) and late (tumor promotion) biological responses to phorbol esters.
D000818:Animals; D001692:Biological Transport; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D002273:Carcinogens; D005260:Female; D066298:In Vitro Techniques; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D007801:Langerhans Cells / Q000187:drug effects / Q000378:metabolism; D008081:Liposomes / Q000378:metabolism; D010703:Phorbol Esters / Q000494:pharmacology*; D010704:Phorbols / Q000494:pharmacology*; D051381:Rats; D013329:Structure-Activity Relationship; D013997:Time Factors; D014783:Viscosity
D002273:Carcinogens; D007328:Insulin; D008081:Liposomes; D010703:Phorbol Esters; D010704:Phorbols; D000001:Calcimycin; D002118:Calcium